File History problems after installing KB5124008, KB5126052,KB5126146, KB5122878, and KB890830

I had the same issue, so uninstalled KB5122878. The Bad: Backup (System Settings) still showed “Your data is not backed up”. The Good: I could once again view “Previous Versions” in the properties panel. The https://support.microsoft.com/en-us/servicing/os/windows-10/2026/09/kb5122878-windows-10-21h2-22h2-security-update referenced Control Panel > System and Security > File History, which isn't my normal path to backup.  

So, I checked Control Panel → File History and it still displayed "File History is On". Pressed “Run” and crossed fingers it would only take a few minutes seeing it was 1-2 days of backup. Success! Backup date adjusted to today 10/1! When I searched "Backup" in System Settings (like normal) it also updated to 10/1/26!!

Ran another backup through the Backup in System Settings and it worked again!